Electronic camera

ABSTRACT

An electronic camera of the present invention includes: an imaging unit capturing a subject to generate an original image; a derivative image generating unit reducing resolution or color of the original image to generate a derivative image for transfer; a recording unit recording the original image and the derivative image thereon such that the original image and the derivative image get associated with each other; and a transfer unit transferring the derivative image recorded on the recording unit to an external transfer destination. In this configuration, the recording unit finds the derivative image (original image) by referring to the association with the original image (or derivative image), thereby collectively managing the original image and the derivative image. This makes it possible to prevent a user from being confused at image management due to the original image and the derivative image being the same image.

This is a Continuation of application Ser. No. 10/380,328 filed Mar. 13,2003, which in turn is a National Stage of PCT/JP02/07111 filed Jul. 12,2002. The entire disclosure of the prior applications is herebyincorporated by reference herein in its entirety.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to an electronic camera which generatesderivative images for external transfer from captured original images.The present invention particularly relates to an image managingtechnology, an image displaying technology, and a user interfacetechnology for these derivative images.

DESCRIPTION OF THE RELATED ART

In recent years, the pixel density of an electronic camera tends toincrease more and more. With this increase in the pixel density, a filespace of an image generated in an electronic camera amounts to 1 Mbyteor more even after compression.

Images generated in an electronic camera are outputted to a personalcomputer, a printer, a mass memory unit, a cellular phone, a digitalphotograph server on the Internet, and so on when necessary.

When an image of, for example, 1 Mbyte or more per frame is transferredto such external transfer destinations, a problem of a long transfertime arises.

Further, for example, a cellular phone or the like handles images withan extremely lower pixel density compared with that of images handled bya personal computer, a printer, and the like. Therefore, in a case wherean image with substantially the same pixel density as images used with apersonal computer or a printer is transferred to a cellular phone, thecellular phone cannot receive the image because the image data exceedsits data capacity, resulting in data loss.

For the purpose of solving this problem, the inventor of the presentapplication has come up with an idea that a derivative image with areduced data size is generated when necessary in an electronic camera touse the derivative image for external transfer.

In this case, however, the derivative image and its original image fromwhich the derivative image is generated both exist in a recording unitof the electronic camera.

This consequently doubles the number of images to be managed in theelectronic camera, and there arises a problem that management of imagesin the electronic camera may be complexed to a great extent.

In particular, since these original image and derivative image are thesame image, a user has a difficulty in clearly distinguishing theoriginal image and the derivative image on the small monitor screen ofthe electronic camera and in accurately selecting from the two. As aresult, the user may mistakenly transfer the original image instead ofthe derivative image or vice versa to the exterior.

DISCLOSURE OF THE INVENTION

In view of solving the above-described problems, it is an object of thepresent invention to provide a technology for appropriately managingderivative images which are generated for use of external transfer.

It is another object of the present invention to provide an imagedisplaying technology for distinguishing between an original image and aderivative image with ease.

It is still another object of the present invention to provide a userinterface technology which achieves an easy and accurate discriminationoperation on an image to be transferred.

Hereinafter, the present invention will be explained.

(1) An electronic camera of the present invention includes: an imagingunit for capturing a subject to generate an original image; a derivativeimage generating unit for reducing resolution or color of the originalimage to generate derivative image(s) for transfer; a recording unitrecording the original image and the derivative image thereon in such amanner that the original image the derivative image get associated witheach other; and a transfer unit transferring the derivative imagerecorded on the recording unit to an external transfer destination.

With this structure, the derivative image (or original image) can bespecified by utilizing its association with its original image (orderivative image). This can realize comprehensive image management ofthe original image and the derivative image with ease based on theoriginal-derivative image associations.

It is preferable that, for example, the recording unit manages thederivative image (or original image) in the same way as it manages itsoriginal image (or derivative image) by making use of the associationsdescribed above. This eliminates the necessity of separately managingthe original image and the derivative image.

(2) In another electronic camera of the present invention, the recordingunit of the electronic camera in the above description (1) includes: afolder in which the original image is recorded; and lower folders beingunder the folder hierarchically and in which the derivative images areseparately recorded depending on their respective image sizes, in orderto manage the derivative images by size in a hierarchical manner.

Such hierarchical management enables appropriate image management of theoriginal image and the derivative image. Especially, using the lowerfolders exclusively for storing the derivative images can prevent a userfrom mistakenly storing the original image in the lower folders, therebyenabling accurate discrimination between the original image and thederivative image in image management.

(3) In another electronic camera of the present invention, the transferunit of the electronic camera in the above description (1) obtainsinformation on the external transfer destination from the externaltransfer destination or a user, and the derivative image generating unitdetermines an image format corresponding to the information on theexternal transfer destination to generate a derivative image accordingto the image format.

By structuring the electronic camera in this way, it is made possible toproperly generate derivative images of the image format suitable for theexternal transfer destination. This can further eliminate the necessityof users' manually changing the image format of the derivative imageevery time the external transfer destination is changed.

(4) In another electronic camera of the present invention, theelectronic camera in the above description (1) further includes an erasecontrol unit for receiving an erase command for the original image froma user. The recording unit erases the original image in compliance withthe erase command, and then retrieves and erases a recorded derivativeimage which is associated with the original image.

By structuring the electronic camera in this way, in accordance to theerase of the original image, its corresponding derivative image is alsoerased. This eliminates a disadvantage that upon erasing an originalimage, the user forgets erasing its derivative images, leaving them inthe electronic camera. In addition, from the users' point of view, theyneed not separately erase the original image and its derivative imagesince what they have to pay attention to is to erase the original image.

(5) In another electronic camera of the present invention, the recordingunit of the electronic camera in the above description (1) erases aderivative image which has been transferred by the transfer unit.Structuring the electronic camera in this way eliminates a disadvantagethat externally transferred derivative images remain in the electroniccamera.(6) Another electronic camera of the present invention is configuredsuch that the electronic camera in the above description (1)additionally includes a storage space monitoring unit for determining anavailable storage space of the recording unit and finding a shortage inthe available storage space. The recording unit erases all or a part ofthe derivative images when the storage space monitoring unit finds ashortage in the available storage space.

It is possible to prevent the accumulation of the derivative images,thereby accordingly solving the shortage in the available storage space.

(7) Another electronic camera of the present invention is characterizedin that the electronic camera in the above description (1) furtherincludes a transfer control unit for receiving from a user a filetransfer command for the original image, and the recording unitfile-transfers the original image in compliance with the file transfercommand and retrieves, for file-transfer, a derivative image which hasbeen recorded in association with original image.

Structuring the electronic camera in this way solves a problem that thederivative image remains at its original position, separately from theoriginal image after the original image is file-transferred. This alsoallows a user to pay attention only to the file transfer of the originalimage, eliminating the necessity for the user to perform the filetransfer of the original image and the derivative image separately.

(8) Another electronic camera of the present invention is characterizedin that the electronic camera in the above description (1) furtherincludes a protect control unit for receiving from a user a protectcommand for the original image, and the recording unit sets a protectattribute on the original image in compliance with the protect command,and retrieves a derivative image which has been recorded in associationwith the original image to set the protect attribute on this derivativeimage.

Structuring the electronic camera in this way solves a problem that thederivative image without the protect attribute is mistakenly erased eventhough its original image has the protect attribute set thereon. Thiseliminates the necessity for the user to set the protect attribute onthe original image and the derivative image separately, allowing theuser to pay attention only to the protect setting on the original image.

(9) Another electronic camera of the present invention is characterizedin that the electronic camera in the above description (1) furtherincludes an original image erase control unit for receiving only anerase command for the original image from a user, in which the recordingunit erases the original image in compliance with the erase command, andretrieves a derivative image which has been recorded in association withthe original image, and upgrades this derivative image to the originalimage.

Structuring the electronic camera in this way can prevent a problem thatthe user forgets that a derivative image having no original imageremains in the electronic camera, leaving the derivative image thereinwithout processing it. Note that the recording unit preferably upgradesa derivative image of the largest image size to an original image when aplurality of corresponding derivative images is present. Moreover, it ispreferable that the recording unit records the original image to whichthe derivative image has been upgraded, in association with remainingderivative images.

(10) Another electronic camera of the present invention is characterizedin that the imaging unit of the electronic camera in the abovedescription (1) selectively has a moving image capture mode in which asubject is captured as moving images, and the derivative imagegenerating unit generates, for the original image captured in the movingimage capture mode (namely, moving images), a derivative image byreducing resolution or color of one frame of the original image.

Such generation of the derivative image from one frame of the movingimages enables reduction in processing load taken for generating thederivative image from the moving images. It is also made possible thatcaptured moving images are not transferred immediately after thecapture, but only one frame of the derivative image is transferred for atrial instead.

(11) Another electronic camera of the present invention is characterizedin that the imaging unit of the electronic camera in the abovedescription (1) selectively has a continuous capture mode in which asubject is captured as continuous static images, in which the derivativeimage generating unit generates, for an original image captured in thecontinuous capture mode (namely, plural static images), derivativeimages (namely, plural static images) by reducing resolution or color ofeach frame of the original image.

Structuring the electronic camera in this way eliminates the necessityfor the user to generate the derivative images frame by frame separatelyfrom the continuously shot static images. This results in realizing avery usable electronic camera.

(12) Another electronic camera of the present invention is characterizedin that the electronic camera in the above description (1) furtherincludes a thumbnail generating unit generating a thumbnail image forthumbnail display from the original image and appending the generatedthumbnail image to the original image, and the thumbnail generating unitdoes not append the thumbnail image to the original image when thenumber of pixels of the thumbnail image is equal to or larger than thenumber of pixels of the derivative image.

Not appending the thumbnail image to the original image can reduce thefile size of the original image properly. Note that the derivative imageis preferably used in place of the thumbnail image in the case of notappending the thumbnail to the original image as described above.

(13) Another electronic camera of the present invention includes: animaging unit for capturing a subject to generate an original image; aderivative image generating unit for reducing resolution or color of theoriginal image to generate a derivative image for transfer; a recordingunit recording the original image and the derivative image thereon; atransfer unit transferring the derivative image recorded on therecording unit to an external transfer destination; and a control uniterasing from the recording unit a derivative image which has beentransferred to exterior by the transfer unit.

Structuring the electronic camera in this way eliminates a problem thatthe derivative image which has been transferred continues to remain inthe electronic camera.

(14) Another electronic camera of the present invention is characterizedin that the electronic camera in the above description (1) furtherincludes a display unit displaying an image or information on the image,wherein the display unit discriminates between the original image andthe derivative image and decides the derivative image as non-display.

In such a structure, not displaying (hiding) the derivative image on thescreen makes it possible to prevent, with sureness, the user from beingconfused because the original image and the derivative image being thesame image appear on the screen. In addition, deciding the derivativeimage as non-display reduces the number of images to be displayed. Thisenables the user to quickly find a target image from a small number ofdisplay images.

(15) Another electronic camera of the present invention is characterizedin that the electronic camera in the above description (1) furtherincludes a display unit displaying an image or information on the image,and the display unit displays information on the image size of thederivative image in addition to the derivative image.

Such a structure of the electronic camera enables the user to accuratelydistinguish the original image and the derivative image being the sameimage, according to the displayed image size.

(16) Another electronic camera of the present invention is characterizedin that the electronic camera in the above description (1) furtherincludes a display unit displaying an image or information on the image,and the display unit displays a derivative image when the user performsa predetermined operation during the display of the original image, anddisplays derivative images in the order of their image sizes accordingto the user's operation when a plurality of derivative images generatedfrom the same original image are present.

With such a structure of the electronic camera, when the predetermineduser's operation is performed during the display of the original image,its corresponding derivative image is displayed. In this case, firstdisplayed is the original image and next is the derivative image,therefore, the user can accurately distinguish the original image andthe derivative image being the same image according to the displayorder.

Further, in a case where a plurality of derivative images generated fromthe same original image are present, the derivative images are displayedin the order of their image sizes according to the user's operation.This enables the user to accurately decide a magnitude relation ofplural images being the same image, according to the display order.

(17) Another electronic camera of the present invention is characterizedin that the electronic camera in the above description (1) furtherincludes a display unit displaying an image or information on the image,and the display unit, upon deciding the original image as non-display,decides a derivative image generated from this original image asnon-display.

Structuring the electronic camera in this way can prevent occurrence ofa problem that a derivative image of the original image as non-displayis displayed. Further, the user need not set non-display twiceseparately for the original image and its derivative image being thesame image, therefore, the user can save his/her labor.

(18) Another electronic camera of the present invention is characterizedin that the electronic camera in the above description (1) furtherincludes a display unit displaying an image or information on the image,and the display unit discriminates between the original image and thederivative image and does not display the original image and thederivative image concurrently on the screen.

In such a structure, the original image and the derivative image beingthe same image are not displayed together on the same screen, which canprevent the user from being confused because of his/her inability todistinguish the images. Further, the original image and the derivativeimage being the same image are not displayed at the same time so thatmany different images can be concurrently displayed. This enables theuser to quickly find a target image from various images in a displaylist.

(19) Another electronic camera of the present invention is characterizedin that the electronic camera in the above description (1) furtherincludes a slide display unit automatically displaying a plurality ofimages in sequence, and the slide display unit separates the pluralityof images into original images and derivative images to automaticallydisplay either of the original images and the derivative images.

Structuring the electronic camera in this way can prevent redundantslide displays of the original images and the derivative images beingthe same image. As a result, the user can look through all images in arelatively short time, or he/she can take his/her time as much as he/shewants to look through all images since it is made possible to elongatethe display time per frame without elongating the total display time.

(20) In another electronic camera of the present invention, the transferunit of the electronic camera in the above description (1) has afunction of transferring the original image in addition to a function oftransferring the derivative image. This electronic camera furtherincludes a transfer setting unit setting a flag on an image designatedby a user's input, the flag indicating a transfer candidate of thetransfer unit. Specifically, the derivative image generating unit ofthis electronic camera, when generating the derivative image from theoriginal image having a flag thereon, removes the flag from thisoriginal image and sets the flag on the generated derivative image.

Such a structure enables the user to freely select an image to betransferred by performing the following operations {circle around (1)}and {circle around (2)}.

{circle around (1)} The user selects an image to be transferred fromoriginal images and temporarily sets the flag on the selected originalimage.{circle around (2)} The user thereafter selects from the original imagesa to-be-transferred image with reduced file space, thereby generating aderivative image.

At this time, the electronic camera shift the flag from the originalimage to the derivative image generated in the operation {circle around(2)}. On the other hand, the original image continues to have the flagin case where the derivative image is not generated from the originalimage. Performing the operations {circle around (1)} and {circle around(2)} enables the user to set the flag on either the original image orthe derivative image when necessary.

The operations {circle around (1)} and {circle around (2)} are bothintended for the original image. Therefore, the user need not payattention to the derivative image when performing these operations, andcan set the flag mainly on original images by an intuitive and simpleoperation.

(21) Another electronic camera of the present invention is so structuredthat the transfer unit of the electronic camera in the above description(1) further has a function of transferring the original image inaddition to a function of transferring the derivative image. Thiselectronic camera further includes a transfer setting unit setting aflag on an image designated by user's input, the flag indicating atransfer candidate of the transfer unit.

Specifically, the transfer setting unit of this electronic camera, whenthe original image selected by the user's input has its derivativeimage, sets the flag not on the original image but on the derivativeimage.

Such a structure enables the user to freely select an image to betransferred by performing the following operations {circle around (3)}and {circle around (4)}.

{circle around (3)} The user selects from original images an image to betransferred with reduced file space and temporarily generates aderivative image.{circle around (4)} The user thereafter selects an image to betransferred from the original images and sets the flag on the selectedoriginal image.

At this time, the electronic camera shifts, at the operation {circlearound (4)}, the flag from the original image to the derivative imagegenerated in the operation. On the other hand, the original imagecontinues to have the flag when the derivative image is not generatedfrom the original image in the operation {circle around (3)}. The usercan allot the flag to the original image and the derivative image whennecessary by performing the operations {circle around (3)} and {circlearound (4)}.

The operations {circle around (3)} and {circle around (4)} are bothintended for the original images. Therefore, the user need not payattention to the derivative image when performing these operation, andcan set the flag mainly on original images by an intuitive and simpleoperation.

Note that it is more preferable to carry out both the inventionsdescribed in (20) and (21) together. In this case, the user is allowedto carry out either the above operations {circle around (1)} and {circlearound (2)} or operations {circle around (3)} and {circle around (4)}.Also, performing the above operations {circle around (1)} and {circlearound (2)} in a reverse order is equivalent to performing theoperations {circle around (3)} and {circle around (4)}. In other words,by combining both of the inventions in (20) and (21), the user isallowed to execute the aforesaid operations {circle around (1)} and{circle around (2)} in any order. This enables the user to set the flagon the original and derivative images more freely without taking theoperation order into account.

(22) Another electronic camera of the present invention is so structuredthat the transfer unit of the electronic camera in the above description(1) further has a function of transferring the original image inaddition to a function of transferring the derivative image. Thiselectronic camera further includes: a transfer setting unit setting aflag on an image designated by user's input, the flag indicating atransfer candidate of the transfer unit; and an erase unit erasing animage designated by a user's input.

Especially, the transfer setting unit of this electronic camera erases,in response to the erase of the original image, a derivative imagegenerated from this original image, and removes the flag from thederivative image.

With such a structure, the user need not remove the flags of remainingderivative images in another time after erasing the original image, andcan operate the electronic camera in a simpler manner.

(23) Another electronic camera of the present invention is so structuredthat the transfer unit of the electronic camera in the above description(1) further has a function of transferring the original image inaddition to a function of transferring the derivative image. Thiselectronic camera further includes: a transfer setting unit setting aflag on an image designated by user's input, the flag indicating atransfer candidate of the transfer unit; and an erase unit erasing animage designated by user's input.

Especially, the transfer setting unit of this electronic camera, whenthe derivative image having the flag set thereon is erased, sets theflag on an original image from which the derivative image is generated.

With such a structure, when the user wants to return the flag to theoriginal image from the derivative image, he/she should first erase anunnecessary derivative image which is no longer a candidate of thetransfer. By this user's operation, the electronic camera shifts theflag from the derivative image to the original image. Therefore, theuser need not shift the flag explicitly, and can operate the electroniccamera in a simpler way.

(24) Another electronic camera of the present invention is so structuredthat the transfer unit of the electronic camera in the above description(1) further has a function of transferring the original image inaddition to a function of transferring the derivative image, Thiselectronic camera further includes a transfer setting unit setting aflag on an image designated by user's input, the flag indicating atransfer candidate of the transfer unit.

Especially, the transfer setting unit of this electronic camera sets theflag on all original images with print information, irrespective ofwhether or not these original images have their derivative images.

The original images having print information are likely to be used forprinting purpose at their external transfer destinations. For theprinting use, the original image having large image information is morepreferable in view of image quality than the derivative image withreduced file space. Hence, setting the flag on the original imageshaving the print information as described above can surely improve theprint image quality at the external transfer destination.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-described objects and other objects of the present inventionwill be made apparent with reference to the following description andthe attached drawings.

FIG. 1( a) and FIG. 1( b) are views each showing an external appearanceof an electronic camera 11;

FIG. 2 is a block diagram explaining the configuration of the electroniccamera 11;

FIG. 3 is a flowchart (1/2) explaining a derivative image generatingprocess;

FIG. 4 is a flowchart (2/2) explaining the derivative image generatingprocess;

FIG. 5 is a flowchart showing a process routine of file manipulation;

FIG. 6 is a flowchart showing a derivative image generating process in asecond embodiment:

FIG. 7 is a flowchart explaining the operation performed in a fullscreen display mode in a third embodiment;

FIG. 8 is a flowchart explaining the operation performed in a thumbnaildisplay mode;

FIG. 9 is a view showing a display screen image in the full screendisplay mode;

FIG. 10 is a view showing a display screen image in the thumbnaildisplay mode;

FIG. 11 is a flowchart explaining the operation performed in a fullscreen display mode in a fourth embodiment;

FIG. 12 is a view showing a display screen image in the full screendisplay mode:

FIG. 13 is a flowchart explaining the operation performed in a slidedisplay mode in the fourth embodiment;

FIG. 14 is a flowchart explaining the operation performed in a fullscreen display mode;

FIG. 15 is a flowchart explaining the operation performed in a thumbnaildisplay mode; and

FIG. 16 shows thumbnail display.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments according to the present invention will beexplained with reference to the drawings.

First Embodiment

A first embodiment is an embodiment of an electronic cameracorresponding to the inventions of claims 1, 4, 5, 7 to 9, 12, and 13.

[Configuration Description of Electronic Camera]

FIG. 1( a) and FIG. 1( b) are views each showing an external appearanceof this electronic camera 11. Note that FIG. 1( a) is a top view of theelectronic camera 11, and FIG. 1( b) is a rear view of the electroniccamera 11. FIG. 2 is a block diagram explaining the internalconfiguration of the electronic camera 11.

Hereinafter, the configuration of the electronic camera 11 will beexplained with reference to these FIG. 1 and FIG. 2.

First, a lens 12 is attached to the electronic camera 11. An imagesensor 13 is disposed in an image space of this lens 12. This imagesensor 13 is controlled by a timing generator 13 a and captures asubject. The image captured by this image sensor 13 (namely, an originalimage) is digitized by an image processing unit 14 and an A/D convertingunit 15, and thereafter, given to a digital signal processor(hereinafter, referred to as a DSP) 16. This DSP 16 is connected to abuffer memory 18 and a memory card 19 via a data bus 17. The DSP 16performs two-dimensional image processing, image compression processing,and so on for the original image while exchanging image data with thisbuffer memory 18. The original image processed in the DSP 16 is recordedon the memory card 19 in an EXIF file format.

Meanwhile, the aforesaid timing generator 13 a, image processing unit14, DSP 16, buffer memory 18, and memory card 19 are connected to amicroprocessor (hereinafter, referred to as an MPU) 21 via a system bus20 for control and data transfer.

To this MPU 21, connected are a release button 22, a cross button 23, amenu button 24, a command dial 25, a zoom button 26, a display switchbutton 27, a transfer button 28, a derivative image generating button29, an enter key 29 a, and an erase button 29 b.

Note that the aforesaid cross button 23 is constituted of four-directionkeys consisting of an up key 23 a, a down key 23 b, a left key 23 c, anda right key 23 d.

A frame memory 30 is connected to the aforesaid system bus 20. Imagedata in this frame memory 30 is displayed on a liquid crystal displayunit 31 provided on a rear face of the electronic camera 11.

To the aforesaid system bus 20, further connected is an interface 32transferring an image having a flag, to an external transfer destinationin response to the operation to the transfer button 28.

[Relation with the Invention]

Hereinafter, the relation between the inventions and the firstembodiment will be explained. It should be noted that the relation hereonly illustrates one interpretation for reference and is not intended tolimit the present invention more than necessary.

An imaging unit described in the claims corresponds to the image sensor13, the timing generator 13 a, the image processing unit 14, the A/Dconverting unit 15, and the DSP 16.

A derivative image generating unit described in the claims correspondsto ‘a derivative image generating function’ of the MPU 21 (or the DSP16).

A recording unit described in the claims corresponds to ‘a function offile management of the memory card 19’ of the MPU 21.

A transfer unit described in the claims corresponds to the interface 32.

An erase control unit described in the claims corresponds to ‘a functionof receiving an erase command for the original image from a user'soperation or the like of the cross button 23’ of the MPU 21.

A transfer control unit described in the claims corresponds to ‘afunction of receiving a file transfer command for an original image froma user's operation or the like of the cross button 23’ of the MPU 21.

A protect control unit described in the claims corresponds to ‘afunction of receiving a protect command for an original image from auser's operation or the like of the cross button 23’ of the MPU 21.

An original image erase control unit described in the claims correspondsto ‘a function of receiving an erase command for only an original imagefrom a user's operation or the like of the cross button 23’ of the MPU21.

A thumbnail generating unit described in the claims corresponds to ‘afunction of generating a thumbnail image to append it to a file headerof an original image’ of the MPU 21 (or the DSP 16).

A control unit described in the claims corresponds to ‘a function oferasing from the memory card 19 a derivative image which has beentransferred’ of the MPU 21.

[Description on Derivative Image Generating Process]

FIG. 3 and FIG. 4 are flowcharts explaining a derivative imagegenerating process. Note that this process starts as a part of processesin response to pressing of the down key 23 b. Hereinafter, thederivative image generating process will be explained following thesteps in FIG. 3 and FIG. 4.

Step S1: When a user presses down the down key 23 b, the MPU 21 firstdetermines a current operation mode of the electronic camera 11.

Here, when the current operation mode is a quick review mode (a mode todisplay on the liquid crystal display unit 31 an image immediately afterbeing captured) or a reproduction mode (a mode to reproduce an image inthe memory card 19 for display on the liquid crystal display unit 31),the MPU 21 shifts its operation to Step S2.

On the other hand, in the case where the current operation mode is ofother operation modes, the MPU 21 shifts its operation to Step S14.

Step S2: The MPU 21 determines a current display status of the liquidcrystal display unit 31.

When the original image is displayed on the full screen, the MPU 21shifts its operation to Step S3.

On the other hand, in the case where the liquid crystal display unit 31has other display status (a ¼ screen display, a thumbnail display, aderivative image display, or the like), the MPU 21 shifts its operationto Step S14.

Step 3: The MPU 21 obtains information on an available storage space ofthe memory card 19.

Here, when the storage space currently available is too small to store anew derivative image, the MPU 21 gives up generating a new derivativeimage and shifts its operation to Step S14.

On the other hand, when the storage space currently available is largeenough to store the derivative image, the MPU 21 shifts its operation toStep 4.

Step S4: The MPU 21 overlappingly displays the following confirmationmenu on a display image on the liquid crystal display unit 31.Header “Generate a derivative image?”Option {circle around (1)} Yes (default option)Option {circle around (2)} NoOption {circle around (3)} Change reduction sizeStep S5: The MPU 21 monitors a user's operation to the cross button 23to receive a selected one of the above options {circle around (1)} to{circle around (3)}.

Specifically, a user hits the right key 23 d once, determining selectionof the option {circle around (1)}. In this case, the MPU 21 shifts itsoperation to Step S8.

The user hits the right key 23 d once after hitting the down key 23 bonce, determining selection of the option {circle around (2)}. In thiscase, the MPU 21 stops generating a new derivative image to shifts itsoperation to Step S14.

Meanwhile, the user hits the right key 23 d once after hitting the downkey 23 b twice, determining selection of the option {circle around (3)}.In this case, the MPU 21 shifts its operation to Step S6.

Step S6: The MPU 21 additionally displays the following confirmationmenu on the display image on the liquid crystal display unit 31.Header “Change reduction size”Option {circle around (1)} 640×480 (default at the shipping time)Option {circle around (2)} 320×240Option {circle around (3)} 160×120Option {circle around (4)} 96×72Step S7: The MPU 21 monitors the user's operation to the cross button 23to receive the selection and determination of the image size (reductionsize) of the derivative image. The MPU 21 uses the image size determinedhere as a default thereafter. After this operation, the MPU 21 shiftsits operation back to Step S4.Step S8: The MPU 21 searches files in the memory card 19 to determinewhether or not a derivative image to be generated already exists.

When the derivative image to be generated already exists here, the MPU21 shifts its operation to Step S9.

On the other hand, when the derivative image to be generated does notexist, the MPU 21 shifts its operation to Step S11.

Step S9: The MPU 21 overlappingly displays the following confirmationmenu on the display image on the liquid crystal display unit 31.Header “A derivative image already generated. Overwrite?”Option {circle around (1)} YesOption {circle around (2)} No (default option)Option {circle around (3)} Change reduction sizeStep S10: The MPU 21 monitors the user's operation to the cross button23 to receive a selected one of the above options {circle around (1)} to{circle around (3)}.

Specifically, the user hits the right key once, determining selection ofthe option {circle around (2)}. In this case, the MPU 21 stopsgenerating a new derivative image to shift its operation to Step S14.

The user hits the right key 23 d once after hitting the down key 23 bonce, determining selection of the option {circle around (3)}. In thiscase, the MPU 21 shifts its operation to Step S6.

Meanwhile, the user hits the right key 23 d once after hitting the upkey 23 a once, determining selection of the option {circle around (1)}.In this case, the MPU 21 shifts its operation to Step S11.

Step 11: In the case of the reproduction mode, the MPU 21 reads out fromthe memory card 19 a compressed file of the original image currentlydisplayed on the liquid crystal display unit 31 to store this compressedfile in the buffer memory 18. The DSP 16 expands this compressed file todevelop the original image in the buffer memory 18.

On the other hand, in the case of the quick review mode, the originalimage immediately after being captured has been developed in the buffermemory 18 by the MPU 21.

The MPU 21 (or the DSP 16) performs resolution-conversion on thisoriginal image in the buffer memory 18 to have an image of a defaultimage size to generate a derivative image.

The DSP 16 compresses this derivative image to, for example, about 1/16irrespective of the compressibility of the original image.

The MPU 21 copies header information of the original image, appends itto the compressed data of the derivative image to generate a compressedfile in the EXIF file format.

Further, the MPU 21 replaces an initial letter of a file name“DSCN****.jpg” of the original image with a letter (for example, “S” orthe like) according to the image size to create a file name of thederivative image. The associations between the original image and thederivative image are made according to the file name rule.

The MPU 21 records thus generated file of the derivative image in thesame folder as the original image in the memory card 19.

Step S12: The MPU 21 compares the number of pixels of a thumbnail imageappended in the file of the original image with the number of pixels ofthe derivative image newly generated.

When the number of the pixels of the thumbnail image is equal to orlarger than the number of the pixels of the derivative image here, theMPU 21 shifts its operation to Step S13.

On the other hand, when the number of the pixels of the thumbnail imageis smaller than the number of the pixels of the derivative image, theMPU 21 shifts its operation to Step S14.

Step S13: The MPU 21 erases the thumbnail image from the file of theoriginal image to reduce a file space of the original image. Thereafter,when the thumbnail image of the original image is required, thederivative image is used as a substitute for the thumbnail image.Step S14: The MPU 21 calls other process routines which are to beexecuted when the down key 23 b is pressed down.

Through the operations explained above, the derivative image generatingprocess is completed.

[Description on File Manipulation of Images]

FIG. 5 is a flowchart showing a process routine of file manipulation.Hereinafter, the file manipulation to images will be explained followingthe steps shown in FIG. 5.

Step S18: The user first switches the mode of the electronic camera 11to the reproduction mode, and selects on the liquid crystal display unit31 an original image as an object of the file manipulation.

Step S19: When the original image as the object of the manipulation isselected, the MPU 21 changes the initial letter of the file name of thisoriginal image to create the file name of a derivative image. The MPU 21searches the memory card 19 for the file name of the derivative imageand determines whether or not the concerning derivative image exists.Step S20: Next, the MPU 21 monitors the user's operation to the menubutton 24 and the transfer button 28.

When the transfer button 28 is pressed down here, the MPU 21 shifts itsoperation to Step S21.

On the other hand, when the menu button 24 is pressed down, the MPU 21shifts its operation to Step S22.

Step S21: When the original image as the object of the manipulation hasa derivative image, the MPU 21 transfers this derivative image to apreset external transfer destination via the interface 32. Uponcompletion of the transfer operation, the MPU 21 erases from the memorycard 19 the derivative image which has been transferred, to therebyincrease an available storage space of the memory card 19.

Meanwhile, when the original image as the object of the manipulationdoes not have any derivative image, the original image is transferred asit is to the external transfer destination via the interface 32.

After such file manipulation, the MPU 21 completes the file manipulationprocess routine.

Step S22: The MPU 21 displays a menu screen on the liquid crystaldisplay unit 31 in response to the menu button 24 being pressed down.The user operates the cross button 23 referring to the menu screen onthe liquid crystal display unit 31 to input a desired file manipulationcommand.Step S23: When the user selects a file erase command to the originalimage, the MPU 21 shifts its operation to Step S24. In other cases, theMPU 21 shifts its operation to Step S25.Step S24: The MPU 21 erases from the memory card 19 the original imageas the object of the manipulation. Note that, when the original image asthe object of the manipulation has a derivative image, the MPU 21 erasesthis derivative image together. After such file manipulation, the MPU 21finishes the file manipulation process routine.Step S25: When the user selects a file transfer command to the originalimage, the MPU 21 shifts its operation to Step S26. In other cases, theMPU 21 shifts its operation to Step S27.Step S26: The MPU 21 file-transfers the original image as the object ofthe manipulation to a folder designated by the user. Note that, when theoriginal image as the object of the manipulation has a derivative image,the MPU 21 file-transfers this derivative image together. After suchfile manipulation, the MPU 21 finishes the file manipulation processroutine.Step S27: When the user selects a protect command for the originalimage, the MPU 21 shifts its operation to Step S28. In other cases, theMPU 21 shifts its operation to Step S29.Step S28: The MPU 21 appends a protect attribute to the file of theoriginal image as the object of the manipulation. Note that, when theoriginal image as the object of the manipulation has a derivative image,the MPU 21 appends the protect attribute to the file of this derivativeimage as well. After such file manipulation, the MPU 21 finishes thefile manipulation process routine.Step S29: When the user selects an erase command to only the originalimage, the MPU 21 shifts its operation to Step S30. In other cases, theMPU 21 finishes the file manipulation process routine.Step S30: The MPU 21 erases the file of the original image as the objectof the manipulation from the memory card 19. Note that, when theoriginal image as the object of the manipulation has a derivative image,the MPU 21 changes the file name of this derivative image to the filename of the original image, thereby upgrading the derivative image tothe original image. After such file manipulation, the MPU 21 finishesthe file manipulation process routine.

Through the operations explained above, the file manipulation process iscompleted.

Effect and so on of First Embodiment

As described above, in the first embodiment, a new derivative image fortransfer is generated by reducing the resolution of the original image.The MPU 21 changes the initial letter “D” of the file name of theoriginal image to the initial letter “S” or the like for the derivativeimage to generate the file name of the derivative image. The originalimage and the derivative image are recorded on the memory card 19 insuch a manner that both the images get associated with each other by thefile name rule.

Therefore, by tracing back the associations by this file name rule, thefile manipulation done to the original image can be automaticallyapplied to its derivative image. As a result, the user need notseparately perform file manipulation for the original image and thederivative image, which realizes saving labor taken for managing thederivative image.

Especially, in the first embodiment, in response to the erase of theoriginal image, its corresponding derivative image is erased together.This eliminates a problem that an unnecessary derivative image continuesto remain on the memory card 19 and occupies a memory space even afterthe original image is erased.

Further, in the first embodiment, the derivative image is erased inresponse to the completion of the external transfer of the derivativeimage. This eliminates a problem that the derivative image that has beentransferred continues to remain in the electronic camera and occupiesthe memory space of the memory card 19.

Moreover, in the first embodiment, in response to the file transfer ofthe original image, its corresponding derivative image is alsofile-transferred. This eliminates a problem that the derivative imageexists separately from the original image after the file transfer of theoriginal image.

In addition, in the first embodiment, in accordance with the protectsetting (erase prevention setting) of the original image, the protectsetting is set on its corresponding derivative image. Therefore, theuser need not set the protect setting separately on the original imageand on the derivative image, which makes it possible to save his/hertime and labor.

Further, in the first embodiment, when only the original image iserased, its corresponding derivative image is upgraded to the originalimage. This can prevent a disadvantage that the user does not notice thederivative image whose original image does not exist remaining on thememory card 19 and leaves it unprocessed.

Moreover, in the first embodiment, if the number of the pixels of thethumbnail image is equal to or larger than the number of the pixels ofthe derivative image, the thumbnail image is erased from the file of theoriginal image. This can reduce the file size of the original image bythe file size of the thumbnail image.

Next, another embodiment will be explained.

Second Embodiment

A second embodiment describes an electronic camera corresponding to theinventions of claims 1 to 13. Note that the configuration of theelectronic camera in the second embodiment is the same as that in thefirst embodiment (FIG. 1 and FIG. 2), and therefore, the configurationdescription thereof will be omitted here. Further, description on theoperations similar to those of the first embodiment (file manipulationto the images, suspension of thumbnail image appending, and so on) willbe omitted here in order to avoid repetition.

[Relation with the Invention]

Hereinafter, the relation between the inventions and the secondembodiment will be explained. Note that the relation here onlyillustrates one interpretation for reference, and is not intended tolimit the present invention more than necessary.

An imaging unit described in the claims corresponds to an image sensor13, a timing generator 13 a, an image processing unit 14, an A/Dconverting unit 15, and a DSP 16.

A derivative image generating unit described in the claims correspondsto ‘a function of generating a derivative image’ of an MPU 21 (or theDSP 16).

A recording unit described in the claims corresponds to ‘a function offile management of a memory card 19’ of the MPU 21.

A transfer unit described in the claims corresponds to an interface 32.

A storage space monitoring unit described in the claims corresponds to‘a function of monitoring an available storage space of the memory card19’ of the MPU 21.

A control unit described in the claims corresponds to ‘a function oferasing from the memory card 19 a derivative image which has beentransferred’ of the MPU 21.

[Description on Derivative Image Generating Process]

FIG. 6 is a flowchart showing a derivative image generating processcharacterizing the second embodiment.

Hereinafter, the derivative image generating process will be explainedfollowing the steps shown in FIG. 6.

Step S40: A user first operates a cross button 23, similarly to thefirst embodiment, to give a derivative image generating command to theMPU 21.Step S41: The MPU 21 obtains information on an available storage spaceof the memory card 19.Step S42: The MPU 21 determines whether or not the available storagespace of the memory card 19 is large enough to store a derivative image.

When the available storage space is too small to store the derivativeimage here, the MPU 21 shifts its operation to Step S42.

On the other hand, when the available storage space is large enough tostore the derivative image, the MPU 21 shifts its operation to Step S43.

Step S43: The MPU 21 erases from the memory card 19 a part or all ofexisting derivative images to secure a memory space in the memory card19.Step S44: The MPU 21 communicates with an external transfer destinationvia the interface 32 to obtain information on the external transferdestination (incidentally, information on what kind of device theexternal transfer destination is may also be obtained through a user'sinput).Step S45: The MPU 21 determines an image format (for example, imagesize, a screen aspect ratio, the number of colors, and so on) of thederivative image appropriate for the external transfer destination inaccordance with the information on the external transfer destination.Step S46: The MPU 21 determines the type of an original image from whichthe derivative image is generated.

When the original image is a one-frame image captured in a single-shotcapture mode here, the MPU 21 shifts its operation to Step S47.

When the original image is constituted of moving images captured in amoving image capture mode, the MPU 21 shifts its operation to Step S48.

On the other hand, when the original image is a group of static imagescaptured in a continuous capture mode, the MPU 21 shifts its operationto Step S49.

Step S47: The MPU 21 converts the original image (the one-frame staticimage here) to the image format determined in Step S45 to generate thederivative image. After this operation, the MPU 21 shifts its operationto Step S50.Step S48: The MPU 21 extracts a first frame of the original image (themoving images here). The MPU 21 converts this first frame into the imageformat determined in Step S45 to generate the derivative image. Afterthis operation, the MPU 21 shifts its operation to Step S50.Step S49: The MPU 21 converts each frame of the original image (theplural static images here) into the image format determined in Step S45to generate the plural derivative images. After this operation, the MPU21 shifts its operation to Step S50.Step S50: The MPU 21 determines whether or not a lower foldercorresponding to the image size of the derivative image exists in afolder of the original image.

When the lower folder does not exist here, the MPU 21 shifts itsoperation to Step S51.

On the other hand, when the lower folder exists, the MPU 21 shifts itsoperation to Step S52.

Step S51: The MPU 21 makes a lower folder exclusively for the image sizeof the derivative image under a hierarchy of the original image folderin the memory card 19.Step S52: The MPU 21 stores a file of the derivative image in the lowerfolder exclusively for the image size.

Through the above-described operations, the derivative image generatingprocess is completed.

Effect and so on of Second Embodiment

In the second embodiment, the same effect as that in the firstembodiment is obtainable as described above.

In addition, in the second embodiment, the lower folder is made for eachimage size of the derivative image in the folder of the original image,and the derivative images are stored therein, being classified by theimage size. This enables efficient image management of the originalimages and the derivative images based on the hierarchical folders.

Further, in the second embodiment, the image format appropriate for theexternal transfer destination is determined based on the information onthe external transfer destination, and the derivative image is generatedso as to conform to the image format. Consequently, the user need notchange the image format or the like for every external transferdestination. Moreover, a suitable derivative image for the externaltransfer destination can be surely generated.

Moreover, in the second embodiment, all or a part of the derivativeimages are erased when the memory card 19 does not have a sufficientavailable storage space. In this case, a shortage in the availablestorage space is compensated by the file space of the erased derivativeimages, so that it is made possible to increase the number of recordableframes of the electronic camera with efficiency.

Note that when the memory card 19 does not have an available storagespace large enough to store a captured original image, a part or all ofthe derivative images may be erased. In this case, it is possible tosecure the storage space for the original image.

Third Embodiment

A third embodiment is an embodiment of an electronic cameracorresponding to the inventions of claims 14 and 18.

Note that the configuration of the electronic camera in the thirdembodiment is the same as that in the first embodiment (FIG. 1 and FIG.2), and therefore, the configuration description thereof will be omittedhere.

[Relation with the Invention]

Hereinafter, the relation between the invention and the third embodimentwill be explained. It should be noted that the relation here onlyillustrates one interpretation for reference and is not intended tolimit the present invention more than necessary.

An imaging unit described in the claims corresponds to an image sensor13, a timing generator 13 a, an image processing unit 14, an A/Dconverting unit 15, and a DSP 16.

A derivative image generating unit described in the claims correspondsto ‘a function of generating a derivative image’ of an MPU 21 (or theDSP 16).

A transfer unit described in the claims corresponds to an interface 32.

A display unit described in the claims corresponds to the MPU 21 and aliquid crystal display unit 31.

[Description on Operation of Full Screen Display Mode]

FIG. 7 is a flowchart explaining the operation performed in a fullscreen display mode in the third embodiment. Hereinafter, the operationin the full screen display mode will be explained following the steps inFIG. 7.

Step S101: A user turns a command dial 25 first to select a reproductionmode. The user further operates a display switch button 27 as requiredto select the full screen display mode.

When the full screen display mode is thus selected, the MPU 21 selects aframe number for the full screen display.

After image capturing, for example, the MPU 21 selects the last framenumber (in other words, a frame number captured most recently) as theframe number for the full screen display.

After image reproduction, for another example, the MPU 21 selects a mostrecently reproduced frame number as the frame number for the full screendisplay.

Step S102: The MPU 21 generates a file name of an original imagecorresponding to the selected frame number based on the selected framenumber and a file name rule.

When the file name rule of original images is, for example,“DSCN****.jpg”, the MPU 21 inserts the frame number in the serial number“****” to generate the file name of the original image.

Step S103: The MPU 21 reads out a compressed file of the original imagefrom a memory card 19 based on the generated file name and stores thiscompressed file in a buffer memory 18. After expanding this compressedfile, the DSP 16 converts the resolution thereof according to the screensize of the liquid crystal display unit 31 and stores this convertedfile in a frame memory 30. The liquid crystal display unit 31 displayson the full screen the original image (the one converted in accordancewith the screen size of a monitor screen) in this frame memory 30.Step S104: The MPU 21 determines whether or not the displayed originalimage has a derivative image for transfer.

When a file name rule of derivative images is, for example,“SSCN****.jpg”, the MPU 21 changes an initial letter of the file name ofthe original image from “D” to “S” to generate a file name of thederivative image. The MPU 21 searches the memory card 19 for this filename of the derivative image to determine whether or not the originalimage has the derivative image.

When the original image has the derivative image here, the MPU 21 shiftsits operation to Step S105.

On the other hand, when the corresponding derivative image does notexist, the MPU 21 shifts its operation to Step S106.

Step S105: The MPU 21 overlappingly displays an information displayindicating that “a derivative image exists” as shown in FIG. 9 on theliquid crystal display unit 31 via the frame memory 30.

After such information display, the MPU 21 shifts its operation to StepS106.

Step S106: The MPU 21 waits for a user's key operation with this fullscreen display on (FIG. 9).

When the user presses down a left key 23 c or a right key 23 d here, theMPU 21 shifts its operation to Step S107.

On the other hand, when the user presses down a derivative imagegenerating button 29, the MPU 21 shifts its operation to Step S108.

Step S107: If the right key 23 d is pressed down here, the MPU 21cyclically moves the frame number for the full screen display oneforward.

On the other hand, if the left key 23 c is pressed down, the MPU 21cyclically moves the frame number for the full screen display onebackward.

After thus changing the frame number, the MPU 21 shifts its operationback to Step S102.

Step S108: The MPU 21 displays the following confirmation menuoverlappingly on a display image on the liquid crystal display unit 31.Header “Generate a derivative image?”Option {circle around (1)} Yes (default option)Option {circle around (2)} NoOption {circle around (3)} Change reduction sizeStep S109: The MPU 21 monitors the user's operation to a cross button 23to receive the selection from the above options {circle around (1)} to{circle around (3)}.

Specifically, the user hits the right key 23 d once, determining theselection of the option {circle around (1)}. In this case, the MPU 21shifts its operation to Step S112.

The user hits the right key 23 d once after hitting a down key 23 bonce, determining the selection of the option {circle around (2)}. Inthis case, the MPU 21 cancels generating a new derivative image andshifts its operation back to Step S106.

On the other hand, the user hits the right key 23 d once after hittingthe down key 23 b twice, determining the selection of the option {circlearound (3)}. In this case, the MPU 21 shifts its operation to Step S110.

Step S110: The MPU 21 additionally displays the following confirmationmenu on the display image on the liquid crystal display unit 31.Header “Change reduction size”Option {circle around (1)} 640×480 (default at the shipping time)Option {circle around (2)} 320×240Option {circle around (3)} 160×120Option {circle around (4)} 96×72Step S111: The MPU 21 monitors the user's operation to the cross button23 to receive the selection of the image size (reduction size) of thederivative image. The MPU 21 uses the image size selected here as adefault thereafter. After this operation, the MPU 21 shifts itsoperation back to Step S108.Step S112: The MPU 21 reads out from the memory card 19 the compressedfile of the original image currently displayed on the liquid crystaldisplay unit 31 to store this compressed file in the buffer memory 18.The DSP 16 expands this compressed file to develop the original image inthe buffer memory 18 (incidentally, when the expanded image in Step S103still exists in the buffer memory 18, this expanded image is preferablyused to omit the original image expanding operation).

The MPU 21 (or the DSP 16) converts the resolution of the original imagein this buffer memory 18 to the default image size to generate aderivative image.

The DSP 16 compresses this derivative image to, for example, about 1/16irrespective of the compressibility of the original image.

The MPU 21 copies header information of the original image and appendsit to compressed data of the derivative image to generate a compressedfile in an EXIF format.

Further, the MPU 21 replaces the initial letter of the file name“DSCN****.jpg” of the original image with a letter (for example, “S” orthe like) according to the image size, and the resultant file name isdefined as a file name of the derivative image.

The MPU 21 records the file of thus completed derivative image in thesame folder as the original image in the memory card 19.

After this operation, the MPU 21 shifts its operation back to Step S106.

Through a series of the operations explained above, the full screendisplay is carried out.

[Description on Operation of Thumbnail Display Mode]

FIG. 8 is a flowchart explaining the operation performed in a thumbnaildisplay mode.

Next, the operation in the thumbnail display mode will be explainedfollowing the steps in FIG. 8.

Step S121: The user turns the command dial 25 first to select thereproduction mode. The user further operates the display switch button27 if necessary to select the thumbnail display mode.

When the thumbnail display mode is thus selected, the MPU 21 decides aframe number at a focus position (an original image for focus selectedfrom a group of thumbnail-displayed images).

After image capturing, for example, the MPU 21 selects the last framenumber (namely, a frame number most recently captured) as the framenumber at the focus position.

After image reproduction, for another example, the MPU 21 selects a mostrecently reproduced frame number as the frame number at the focusposition.

Step S122: Based on the selected frame number and the file name rule,file names of the group of the original images for the thumbnail displayare generated.Step S123: The MPU 21 retrieves these file names from the memory card 19and sequentially reads out the thumbnail images each stored in a headerof each file. The MPU 21 displays these thumbnail images as a list onthe liquid crystal display unit 31 via the frame memory 30.Step S124: The MPU 21 determines whether or not each of the originalimages on the screen has a derivative image based on the file name rule.The MPU 21 displays information indicating that “a derivative imageexists” on the thumbnail image corresponding to the original imagehaving the derivative image, as shown in FIG. 10.Step S125: The MPU 21 waits for a user's key operation with thisthumbnail display on.

If the user presses down the derivative image generating button 29 here,the MPU 21 shifts its operation to Step S126.

Meanwhile, when the user presses down a cross button 23, the MPU 21shifts its operation to Step S127.

When the user presses down an enter key, the MPU 21 shifts its operationto Step S131.

Step S126: In case where the derivative image generating button 29 ispressed down here, the MPU 21 displays a derivative image generationmark on each of the thumbnail images at the focus positions, as shown inFIG. 10. Further, the MPU 21 adds the frame number of this focusposition in a derivative image generation schedule list which isprepared on an internal memory. After this operation, the MPU 21 shiftsits operation back to Step S125.Step S127: The MPU 21 determines the user's operation to the crossbutton 23.

If the user presses the down key 23 b down here, the MPU 21 shifts itsoperation to Step S128.

On the other hand, when the user presses down the left key 23 c or theright key 23 d, the MPU 21 shifts its operation to Step S129.

Step S128: The MPU 21 searches for the derivative image of the originalimage at the focus position, and displays as information image size ofthis derivative image on the thumbnail image at the focus position(refer to FIG. 10).

Note that when the original image at the focus position has a pluralityof derivative images, the MPU 21 displays the image sizes of thederivative images in sequence every time the down key 23 b is presseddown.

After this operation, the MPU 21 shifts its operation back to Step S125.

Step S129: When the right key 23 d is pressed down, the MPU 21 moves thefocus position forward by one frame.

On the other hand, when the left key 23 c is pressed down, the MPU 21moves the focus position backward by one frame.

Step S130: In accordance with such shift in the focus position, the MPU21 determines whether or not the focus position shifts to the outside ofa thumbnail display range.

When the focus position shifts within the thumbnail display range here,the MPU 21 shifts its operation back to Step S125.

On the other hand, when the focus position shifts to the outside of thethumbnail display range, the MPU 21 shifts its operation back to StepS122 and updates the thumbnail display.

Step S131: When the enter key 29 a is pressed down, the MPU 21overlappingly displays the following confirmation menu on the liquidcrystal display unit 31.Header “Generate a derivative image?”Option {circle around (1)} Yes (default option)Option {circle around (2)} NoOption {circle around (3)} Change reduction sizeStep S132: The MPU 21 monitors the user's operation to the cross button23 to receive the selection from the above options {circle around (1)}to {circle around (3)}.

When the option {circle around (1)} is selected here, the MPU 21 shiftsits operation to Step S135.

When the option {circle around (2)} is selected, the MPU 21 cancelsgenerating a new derivative image and shifts its operation back to StepS125.

On the other hand, when the option {circle around (3)} is selected, theMPU 21 shifts its operation to Step S133.

Step S133: The MPU 21 additionally displays the following confirmationmenu on the display image on the liquid crystal display unit 31.Header “Change reduction size”Option {circle around (1)} 640×480 (default at the shipping time)Option {circle around (2)} 320×240Option {circle around (3)} 160×120Option {circle around (4)} 96×72Step S134: The MPU 21 monitors the user's operation to the cross button23 to receive the selection of the image size (reduction size) of thederivative image. The MPU 21 uses the image size selected here as adefault thereafter. After this operation, the MPU 21 shifts itsoperation back to Step S131.Step S135: The MPU 21 sequentially generates the derivative images fromthe original images with the generation mark (the original images listedin the derivative image generation schedule list) and sequentiallyrecords these derivative images in the memory card 19.

After this operation, the MPU 21 shifts its operation back to Step S125.

Effect and so on of Third Embodiment

As described above, in the third embodiment, the original image and thederivative image are discriminated based on the file name rule and onlythe original image is displayed on the liquid crystal display unit 31.This makes it possible to surely prevent the user from being confused atimage management since there is no case where the original image and thederivative image being the same image are displayed together.

Further, only the original image is an object of display so that thenumber of images to be displayed is decreased.

This enables the user to quickly find a target image (picture) from asmall number of images.

Moreover, also in the thumbnail display mode, only the original imagesare displayed and thus the original images and the derivative images arenot displayed concurrently on the screen. This can surely prevent theuser from being confused at the image management because the originalimage and the derivative image being the same image are both present onthe screen.

Next, another embodiment will be explained.

Fourth Embodiment

A fourth embodiment is an embodiment of an electronic cameracorresponding to the inventions of claims 15 to 19.

Note that the configuration of the electronic camera in the fourthembodiment is the same as that in the third embodiment (FIG. 1 and FIG.2), and therefore, the configuration description thereof will be omittedhere. Further, description on the same operations as those of the thirdembodiment (the operation in the thumbnail display mode and so on) willbe also omitted in order to avoid repeated description.

[Relation with the Invention]

Hereinafter, the relation between the inventions and the fourthembodiment will be explained. It should be noted that the relation hereonly illustrates one interpretation for reference and is not intended tolimit the present invention more than necessary.

An imaging unit described in the claims corresponds to an image sensor13, a timing generator 13 a, an image processing unit 14, an A/Dconverting unit 15, and a DSP 16.

A derivative image generating unit described in the claims correspondsto ‘a function of generating a derivative image’ of an MPU 21 (or theDSP 16).

A transfer unit described in the claims corresponds to an interface 32.

A display unit described in the claims corresponds to the MPU 21 and aliquid crystal display unit 31.

A slide display unit described in the claims corresponds to the MPU 21and the liquid crystal display unit 31.

[Description on Operation of Full Screen Display Mode]

FIG. 11 is a flowchart explaining the operation performed in a fullscreen display mode in the fourth embodiment. In this FIG. 11, the samestep numbers are assigned to the same operations as those in the thirdembodiment (FIG. 7), and repeated description thereof will be omittedhere.

The operation in the full screen display mode shown in FIG. 11 ischaracterized in that Steps S141 to S143 are newly added. Hereinafter,this added part will be explained. Step S141: The MPU 21 reads out froma memory card 19 a file property of an original image which is to bedisplayed, and determines whether or not this original image is set asnon-display.

When the original image is set as non-display here, the MPU 21 shiftsits operation to Step S142.

On the other hand, when the original image is not set as non-display(when the display thereof is permitted), the MPU 21 shifts its operationto Step S103.

Step S142: The MPU 21 cyclically moves a frame number which is to bedisplayed, by one frame forward and so controls that the original image(and a derivative image) set as non-display is not displayed on thescreen. After this operation, the MPU 21 shifts its operation back toStep S102.Step S143: When a down key 23 b is pressed down in Step S106, the MPU 21replaces an initial letter of a file name “DSCN****.jpg” of the originalimage with a letter (for example, “S” or the like) according to theimage size to generate a file name of the derivative image. The MPU 21searches the memory card 19 for this derivative image. Upon finding thisderivative image, the MPU 21 reads out this derivative image from thememory card 19, and displays a display 42 of this derivative imageoverlappingly on a full screen display 41 of the original image, asshown in FIG. 12. At this time, the MPU 21 also displays an icon 43 asinformation showing the image size of this derivative image.

Note that when the down key 23 b is pressed down a plurality of times,the MPU 21 sequentially displays a plurality of derivative images in thedescending order of the image size. FIG. 12 shows a state in which theplural derivative images are displayed by this operation in a nestingway.

[Description on Operation of Slide Display Mode]

FIG. 13 is a flowchart explaining the operation performed in a slidedisplay mode in the fourth embodiment. Hereinafter, the operation in theslide display mode will be explained following the steps in FIG. 13.

Step S161: A user first turns a command dial 25 to select a reproductionmode. The user further operates a display switch button 27 as requiredto select the slide display mode.

When the slide display mode is thus selected, the MPU 21 selects aninitial frame number of slide display from the memory card 19, andsubstitutes this frame number in a frame number N.

Step S162: A file name of the original image corresponding to the framenumber N is generated based on the frame number N and a file name rule.

When the file name rule of original images is, for example,“DSCN****.jpg”, the MPU 21 inserts the frame number in the serial number“****” to generate the file name of the original image.

Step S163: The MPU 21 obtains information on a file property from thememory card 19 based on the generated file name of the original imageand determines whether or not the original image is set as non-display.

When the original image is set as non-display here, the MPU 21 shiftsits operation to Step S164.

On the other hand, the original image is not set as non-display (whenthe display thereof is permitted), the MPU 21 shifts its operation toStep S165.

Step S164: The MPU 21 moves the frame number to be displayed by oneframe forward cyclically and so controls that the original image set asnon-display is not displayed on the screen. After this operation, theMPU 21 shifts its operation back to Step S162.Step S165: The MPU 21 reads out a compressed file of the original imagefrom the memory card 19 based on the generated file name of the originalimage and stores this compressed file in a buffer memory 18. Afterexpanding this compressed file, the DSP 16 converts the resolutionthereof according the screen size of the liquid crystal display unit 31and stores the converted file in a frame memory 30. The liquid crystaldisplay unit 31 displays the original image (the one converted accordingto the screen size of a monitor screen) stored in this frame memory 30.Step S166: The MPU 21 determines whether or not the original image ondisplay has a derivative image for transfer.

When the original image on display has the derivative image here, theMPU 21 shifts its operation to Step S167.

On the other hand, when the original image on display does not have thederivative image, the MPU 21 shifts its operation to Step S168.

Step S167: The MPU 21 overlappingly displays an information displayindicating that “a derivative image exists” on the liquid crystaldisplay unit 31 via the frame memory 30. After such information display,the MPU 21 shifts its operation to Step S168.Step S168: The MPU 21 waits for the elapse of a slide display timecorresponding to one frame and shifts its operation to Step S169.Step S169: The MPU 21 determines whether or not the current frame numberN is the last frame number in the memory card 19.

When the current frame number N is different from the last frame number,the MPU 21 shifts its operation back to Step S164.

On the other hand, when the current frame number N is the last framenumber, the slide display operation is finished.

Effect and so on of Fourth Embodiment

As described above, in the fourth embodiment, the information display onthe image size of the derivative image is displayed as shown in FIG. 12.This enables a user to appropriately distinguish the original image andthe derivative image being the same image based on the information onthe image size.

Further, in the fourth embodiment, when the down key 23 b is presseddown while the original image is displayed on the full screen, thederivative images are displayed in the descending order of the imagesize. In this case, the user can appropriately distinguish the originalimage and the derivative image based on the display order.

Moreover, in the fourth embodiment, when the original image is set asnon-display, the derivative image is also set as non-display togetherwith the original image. Therefore, the user need not separately set thederivative image as non-display, which can save the user's time andlabor.

Further, in the fourth embodiment, the original image and the derivativeimage are discriminated based on the file name rule and only theoriginal image is displayed in the slide display mode. Therefore, theoriginal image and the derivative image being the same image are notredundantly and repeatedly displayed, which enables the user to lookthrough a series of images in as short a time as possible.

Fifth Embodiment

A fifth embodiment is an embodiment of an electronic cameracorresponding to the inventions of claims 20 to 24.

Note that since the configuration of the electronic camera in the fifthembodiment is the same as that in the first embodiment (FIG. 1 and FIG.2), the configuration description thereof will be omitted here.

[Relation with the Invention]

Hereinafter, the relation between the inventions and the fifthembodiment will be explained. It should be noted that the relation hereonly illustrates one interpretation for reference and is not intended tolimit the present invention more than necessary.

An imaging unit described in the claims corresponds to an image sensor13, a timing generator 13 a, an image processing unit 14, an A/Dconverting unit 15, and a DSP 16.

A derivative image generating unit described in the claims correspondsto “a function of generating a derivative image” of an MPU 21 (or theDSP 16).

A transfer setting unit described in the claims corresponds to ‘afunction of setting a flag on an image’ of the MPU 21.

A transfer unit described in the claims corresponds to an interface 32.

An erase unit described in the claims corresponds to “a function oferasing an image in a memory card 19” of the MPU 21.

[User Interface in Full Screen Display Mode]

FIG. 14 is a flowchart explaining the operation performed in a fullscreen display mode in the fifth embodiment. Hereinafter, the operationin the full screen display mode will be explained following the steps inFIG. 14.

Step S201: A user first turns a command dial 25 of an electronic camera11 to select a reproduction mode. The user further operates a displayswitch button 27 as required to select the full screen display mode.

When the full screen display mode is thus selected, the MPU 21 selects aframe number of an image for the full screen display.

After image capturing, for example, the MPU 21 selects the last framenumber (namely, a frame number most recently captured) as the framenumber for the full screen display.

After the image reproduction, for example, the MPU 21 selects a mostrecently reproduced frame number as the frame number for the full screendisplay.

Step S202: The MPU 21 generates a file name of an original imagecorresponding to the selected frame number based on the selected framenumber and a file name rule.

When the file name rule of original images is, for example,“DSCN:****.jpg”, the MPU 21 inserts the frame number in place of theserial number “****” to generate the file name of the original name.

Step S203: The MPU 21 reads out a compressed file of the original imagefrom the memory card 19 based on the generated file name and stores thiscompressed file in a buffer memory 18. After expanding this compressedfile, the DSP 16 converts the resolution according to the screen size ofa liquid crystal display unit 31, and stores this converted file in aframe memory 30. The liquid crystal display unit 31 displays on the fullscreen the original image (the one converted in accordance with thescreen size of a monitor screen) stored in this frame memory 30.Step S204: With this full screen display, the MPU 21 determines a keyoperation to a cross button 23 by a user.

When the user presses down a left key 23 c or a right key 23 d here, theMPU 21 shifts its operation to Step S205.

When the user presses down a down key 23 b, the MPU 21 shifts itsoperation to Step S206.

In other cases, the MPU 21 shifts its operation to Step S208.

Step S205: When the right key 23 d is pressed down, the MPU 21 moves theframe number for the full screen display one forward cyclically.

On the other hand, when the left key 23 c is pressed down, the MPU 21moves the frame number for the full screen display one backwardcyclically.

After thus changing the frame number, the MPU 21 shifts its operationback to Step S202.

Step S206: The MPU 21 determines whether or not the original image ondisplay has a derivative image.

When a file name rule of derivative images is, for example,“SSCN****.jpg”, the MPU 21 changes an initial letter of the file name ofthe original image from “D” to “S” to generate a file name of thederivative image. The MPU 21 searches the memory card 19 for this filename of the derivative image, thereby judging whether or not theoriginal image has the derivative image.

When the original image has the derivative image here, the MPU 21 shiftsits operation to Step S207.

On the other hand, the corresponding derivative image does not exist,the MPU 21 shifts its operation back to Step S204.

Step S207: The MPU 21 reads out from the memory card 19 the derivativeimage which is generated from the original image on display. The MPU 21displays a display 42 of this derivative image overlappingly on a fullscreen display 41 of the original image, as shown in FIG. 12. At thistime, the MPU 21 also displays as information an icon 43 indicating theimage size of this derivative image together.

Note that when the down key 23 b is pressed down a plurality of times,the MPU 21 sequentially displays a plurality of derivative images in thedescending order of the image size. FIG. 12 shows a state in which theplural derivative images are displayed by this operation in a nestingway.

After this display operation to the derivative image, the MPU 21 shiftsits operation back to Step S204.

Step S208: Further, the MPU 21 determines other user's key operations.

When the MPU 21 recognizes the key operation to a transfer button 28here, the MPU 21 shifts its operation to Step S209.

When the MPU 21 recognizes the key operation to an erase button 29 b,the MPU 21 shifts its operation to Step S213.

In other cases, the MPU 21 shifts its operation to Step S221.

Step S209: The MPU 21 determines whether or not the original image ondisplay has a derivative image.

When the original image has the derivative image here, the MPU 21 shiftsits operation to Step S210.

On the other hand, when the corresponding derivative image does notexist, the MPU 21 shifts its operation to Step S211.

Step S210: The MPU 21 determines whether or not the original image ondisplay has any print information (specification of a frame to beprinted, the number of sheets to be printed, and so on) specified inDPOF (abbreviation of Digital Print Order Format) and the like.

When the original image on display has the print information, the MPU 21shifts its operation to Step S211.

On the other hand, when the original image on display does not have anyprint information, the MPU 21 shifts its operation to Step S212.

Step S211: The MPU 21 sets a flag on the original image on display. Thisflag is set in such a manner, for example, that the MPU 21 writesinformation indicating a transfer candidate in a header or the like ofan image file. Another example of how the flag is set is that the MPU 21adds an identifier (file name or the like) of the image to a transfercandidate list on an internal memory.

After the setting operation, the MPU 21 shifts its operation back toStep S204.

Step S212: The MPU 21 sets the flag not on the original image on displaybut on the derivative image that the original image has.

After this setting operation, the MPU 21 shifts its operation back toStep S204.

Step S213: The MPU 21 determines whether or not the derivative image isdisplayed on the screen.

When the derivative image is displayed here as shown in FIG. 12, the MPU21 shifts its operation to Step S218.

On the other hand, when only the original image is displayed on thescreen, the MPU 21 shifts its operation to Step S214.

Step S214: The MPU 21 erases the original image on display from thememory card 19.Step S215: The MPU 21 determines whether or not the erased originalimage had a derivative image.

When the erased original image had the derivative image here, the MPU 21shifts its operation to Step S216.

On the other hand, when the erased original image does not have thederivative image, the MPU 21 shifts its operation to Step S217.

Step S216: The MPU 21 erases the derivative image that the originalimage had. Further, when the flag has been set on this derivative image,the MPU 21 removes the flag.

Note that when the flag is set as information in the header of the imagefile, removal of this flag is done concurrently with the file erase ofthe derivative image. Also, when setting the flag is managed accordingto the transfer candidate list on the internal memory of the MPU 21, theremoval of the flag is done at the same time as the identifier of animage as a transfer candidate is removed from this transfer candidatelist.

Step S217: The MPU 21 moves the frame number of the original image to bedisplayed by one frame backward in accordance with the erase of theoriginal image. Thereafter, the MPU 21 shifts its operation back to StepS202 and updates the full screen display.Step S218: The MPU 21 determines whether or not a flag is set on thederivative image displayed on the utmost front window of the screen.

When this derivative image has the flag set here, the MPU 21 shifts itsoperation to Step S219.

On the other hand, when this derivative image does not have the flagset, the MPU 21 shifts its operation to Step S220.

Step S219: The MPU 21 sets the flag on the original image from whichthis derivative image is generated. Note that when one original imagehas a plurality of derivative images, the MPU 21 sets the flag on aderivative image having the second largest image size next to thederivative image displayed on the utmost front window.Step S220: The MPU 21 erases from the memory card 19 the derivativeimage displayed on the utmost front window. Further, in a case wherethis derivative image has a flag, the MPU 21 removes the flag at thesame time.

After this operation, the MPU 21 shifts its operation back to Step S202and updates the full screen display.

Step S221: The MPU 21 determines a key operation to a derivative imagegenerating button 29 by a user.

When the MPU 21 recognizes the user's key operation to the derivativeimage generating button 29 here, the MPU 21 shifts its operation to StepS222.

On the other hand, when the MPU 21 does not recognize the key operationto the derivative image generating button 29, the MPU 21 shifts itsoperation back to Step S204.

Step S222: The MPU 21 reads out from the memory card 19 the compressedfile of the original image currently displayed and stores thiscompressed file in the buffer memory 18. The DSP 16 expands thiscompressed file to develop the original image stored in the buffermemory 18 (incidentally, when the expanded image in Step S203 stillexists in the buffer memory 18, it is preferable to use this image,thereby omitting the original image expanding operation).

The MPU 21 (or the DSP 16) converts the resolution of this originalimage in the buffer memory 18 to generate a derivative image.

The DSP 16 compresses this derivative image to, for example, about 1/16irrespective of the compressibility of the original image.

The MPU 21 copies header information of the original image and appendsit to compressed data of the derivative image to generate a compressedfile in an EXIF format.

Further, the MPU 21 replaces the initial letter of the file name“DSCN****.jpg” of the original image with a letter (for example, “S” orthe like) according to the image size to generate a file name of thederivative image.

The MPU 21 records thus generated file of the derivative image in thesame folder as the original image in the memory card 19.

Step S223: The MPU 21 determines whether or not the flag is set on theoriginal image currently on display.

When this original image has the flag set here, the MPU 21 shifts itsoperation to Step S224.

On the other hand, when this original image does not have the flag set,the MPU 21 shifts its operation back to Step S204.

Step S224: The MPU 21 removes the flag on the original image currentlyon display, and sets the flag on a newly generated derivative image.

After this operation, the MPU 21 shifts its operation back to Step S204.

Through a series of the operations explained above, the full screendisplay is carried out.

[User Interface in Thumbnail Display Mode]

FIG. 15 is a flowchart explaining the operation performed in a thumbnaildisplay mode.

Next, the operation in the thumbnail display mode will be explainedfollowing the steps in FIG. 15.

Step S241: The user first turns the command dial 25 of the electroniccamera 11 to select the reproduction mode. The user further operates thedisplay switch button 27 as required to select the thumbnail displaymode.

When the thumbnail display mode is thus selected, the MPU 21 determinesa frame number of a focus position (an original image selected forfocusing among a group of images displayed in the thumbnail displaymode).

After image capturing, for example, the MPU 21 selects the last framenumber (that is, a frame number most recently captured) as the framenumber of the focus position.

After image reproduction, for another example, the MPU 21 selects a mostrecently reproduced frame number as the frame number of the focusposition.

Step S242: The MPU 21 generates file names of a group of original imagesfor the thumbnail display in sequence based on the selected frame numberand the file name rule.Step S243: The MPU 21 retrieves these file names from the memory card 19and sequentially reads out thumbnail images stored in a header or thelike of each file. The MPU 21 stores these thumbnail images in the framememory 30, and displays these thumbnail images as a list on the liquidcrystal display unit 31, as shown in FIG. 16. At this time, the image atthe focus position is highlighted (using a dotted frame or the like asshown in FIG. 16).Step S244: The MPU 21 determines whether or not the original image onthe screen has a derivative image based on the file name rule. As forthe original image having the derivative image, the MPU 21 displaysinformation indicating that “a derivative image exists” on acorresponding thumbnail image, as shown in FIG. 16.Step S245: The MPU 21 determines the user's key operation to the crossbutton 23 in this thumbnail display state.

When the user presses down the down key 23 b here, the MPU 21 shifts itsoperation to Step S246.

When the user presses down the left key 23 c or the right key 23 d, theMPU 21 shifts its operation to Step S247.

In other cases, the MPU 21 shifts its operation to Step S249.

Step S246: The MPU 21 retrieves the derivative image of the originalimage at the focus position, and displays information on the image sizeof this derivative image on the thumbnail image at the focus position(refer to FIG. 16).

Note that when the original image at the focus position has pluralderivative images, the MPU 21 displays the image sizes of the derivativeimages in the descending order every time the down key 23 b is presseddown.

After this operation, the MPU 21 shifts its operation back to Step S245.

Step S247; When the right key 23 d is pressed down, the MPU 21 moves thefocus position by one frame forward.

On the other hand, when the left key 23 c is pressed down, the MPU 21moves the focus position by one frame backward.

Step S248: In accordance with such shift of the focus position, the MPU21 performs scroll shifting of a thumbnail view so as to keep the focusposition within the screen.

After this operation, the MPU 21 shifts its operation back to Step S245.

Step S249: The MPU 21 further determines a user's operation to otherkeys.

When the MPU 21 recognizes the key operation to the derivative imagegenerating button 29 here, the MPU 21 shifts its operation to Step S250.

When the MPU 21 recognizes the key operation to the erase button 29 b,the MPU 21 shifts its operation to Step S251.

In other cases, the MPU 21 shifts its operation to Step S252.

Step S250: When the derivative image generating button 29 is thuspressed down, the MPU 21 displays a derivative image generation mark onthe thumbnail image at the focus position. Further, the MPU 21 adds theframe number of this focus position to a derivative image generationschedule list which is prepared on the internal memory. After thisoperation, the MPU 21 shifts its operation back to Step S245.Step S251: When the erase button 29 b is pressed down here, the MPU 21displays a derivative image erase mark on the thumbnail image at thefocus position. Further, the MPU 21 adds the frame number of this focusposition to a derivative image erase schedule list which is prepared onthe internal memory. After this operation, the MPU 21 shifts itsoperation back to Step S245.Step 252: The MPU 21 further determines the user's operation to otherkeys.

When the MPU 21 recognizes the key operation to the transfer button 28here, the MPU 21 shifts its operation to Step S253.

Meanwhile, when the MPU 21 recognizes the key operation to an enter key29 a, the MPU 21 shifts its operation to Step S257.

In other cases, the MPU 21 shifts its operation back to Step S245.

Step S253: The MPU 21 determines whether or not the original image atthe focus position has a derivative image.

When the original image has the derivative image here, the MPU 21 shiftsits operation to Step S254.

On the other hand, when no corresponding derivative image exists, theMPU 21 shifts its operation to Step S255.

Step S254: The MPU 21 determines whether or not the original image atthe focus position has any print information (specification of a frameto be printed, the number of sheets to be printed, and so on) which isspecified in DPOF (abbreviation of Digital Print Order Format) or thelike.

When the original image has the print information here, the MPU 21shifts its operation to Step S255.

On the other hand, when the original image on display does not have anyprint information, the MPU 21 shifts its operation to Step S256.

Step S255: The MPU 21 sets the flag on the original image at the focusposition.

After this setting operation, the MPU 21 shifts its operation back toStep S245.

Step S256: The MPU 21 sets the flag not on the original image at thefocus position but on the derivative image that this original image has.

After this setting operation, the MPU 21 shifts its operation back toStep S245.

Step S257: The MPU 21 selects the original image with the derivativeimage erase mark (the original image listed in the derivative imagegeneration schedule list) and erases this original image together withthe derivative image. Note that when the derivative image has the flag,the MPU 21 removes this flag as well.Step S258: The MPU 21 selects the original images with the derivativeimage generation mark (the original images listed in the derivativeimage generation schedule list) to generate the derivative images insequence and records them in sequence on the memory card 19. Note thatwhen the original image has the flag, the MPU 21 removes the flag fromthe original image and sets the flag on a newly generated derivativeimage.

After this operation, the MPU 21 shifts its operation back to Step S245.

Through a series of the operations explained above, the operation duringthe thumbnail display is carried out.

[Description on Image Transfer Operation]

Next, the outline of an image transfer operation by the electroniccamera 11 will be explained.

The user first connects the interface 32 of the electronic camera 11 toan external transfer destination via an appropriate transfer route (acable, a wireless LAN, an Internet terminal, and the like).

The user turns a command dial 25 in this state to set the electroniccamera 11 in a transfer mode.

The MPU 21 waits for a user's operation to a transfer button 28according to such a transfer mode. When the user presses down thetransfer button 28, the MPU 21 selects a file of an image having theflag, and transfers this image to the external transfer destinationaccording to a predetermined protocol.

Effect and so on of Fifth Embodiment

As explained above, in generating the derivative image from the originalimage having the flag, the electronic camera 11 removes the flag fromthe original image and sets the flag on the derivative image (refer toSteps S222 to S224 in FIG. 14 and Step 258 in FIG. 15).

This enables the user to freely set the flag on the original image andthe derivative image by a two-step operation of {circle around (1)}setting the flag on the original image and {circle around (2)}generating the derivative image from the original image.

Further, when the original image having the flag set on has thederivative image, the electronic camera 11 does not set the flag on thisoriginal image but sets the flag on the derivative image (refer to StepsS209 to S212 in FIG. 14 and Steps S253 to S256 in FIG. 15).

This enables the user to freely allot the flag to the original image andthe derivative image by a two-step operation of {circle around (3)}generating the derivative image from the original image and {circlearound (4)} setting the flag on the original image.

Since these operations are all intended for the original image, the userneed not directly deal with the derivative image in spite that thederivative image is actually processed. This enables the user to set theflag in an intuitive and simple manner, focusing on the operation on theoriginal image.

Moreover, in the fifth embodiment, in accordance with the erase of theoriginal image, the derivative image generated from this original imageis erased, and further, the flag on this derivative image is alsoremoved (refer to Steps S214 to S216 in FIG. 14 and Step S257 in FIG.15). Consequently, the removal of the flag of the derivative image andthe erase of the derivative image can be carried out at the same time byonly a single operation of erasing the original image. As a result,unnecessary image files in the memory card 19 can be easily erased.

Further, in the fifth embodiment, when the derivative image having theflag is erased, the flag is returned to the original image from whichthe derivative image is generated (refer to Steps S218 to S220 in FIG.14). Therefore, the user only needs to erase the derivative image whenthe user intends to transfer the original image instead of thederivative image with the flag. In this case, the flag need not be newlyset on the original image, which makes it possible to facilitate theoperation of the electronic camera 11.

In addition, in the fifth embodiment, as for the original image havingthe print information (for example, the number of sheets to be printed,print size, image processing information to be referred to at the timeof printing, and so on), the flag is set on the original imageirrespective of existence or nonexistence of the derivative image (referto Steps S210 to S211 in FIG. 14 and Steps S254 to S255 in FIG. 15).

For printing use, generally, the original image is more suitable thanthe derivative image in view of image quality because the original imagehas abundant image information compared to the derivative image withreduced data capacity. Hence, in a case where the original image has theprint information, the original image is preferentially given the flageven when it has derivative images. This results in enhancing the printimage quality with reliability when the images are used for printingpurpose at the external transfer destination.

Additional Comments on Embodiments

Note that in the above-described embodiments the resolution of theoriginal image is reduced to generate the derivative image. The presentinvention, however, is not to be limited thereto. For example, thederivative image is generated by reducing the color of the originalimage.

Further, in the above-described embodiments, the use of the file namerule and the hierarchical folders establishes the associations betweenthe original image and the derivative image. The present invention,however, is not to be limited thereto. For example, the fileassociations between the original image and the derivative image may berecorded by using data such as header information of files and filemanagement information on a recording medium. Further, the originalimage and the derivative image may be discriminated by use of, forexample, header information of files, file management information, imagesize, or the like.

The present invention may be embodied in other specific forms withoutdeparting from the spirit and essential characteristics thereof.Therefore, the above-described embodiments are to be considered in allrespects only as illustrative and no restrictive. The scope of thepresent invention is to be defined by the scope of the patent claims andis not at all to be restricted by the description in the specification.Further, all modifications and changes which come within the meaning andrange of equivalency of the claims are intended to be embraced in thescope of the present invention.

1. An electronic camera comprising: an imaging unit for capturing asubject to generate an original image; a derivative image generatingunit for reducing resolution or color of the original image to generatederivative image(s) which is/are used for transfer; a recording unit forrecording the original image and the derivative image thereon such thatthe original image and the derivative image get associated with eachother; and a transfer unit for transferring the derivative imagerecorded on said recording unit to an external transfer destination.